An Energy-Efficient Micropower Neural Recording Amplifier
An Energy-Efficient Micropower Neural Recording Amplifier
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DOI：
10.1109/tbcas.2007.907868
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发表时间：
2007-06-01
影响因子：
5.1
通讯作者：
Sarpeshkar, Rahul
中科院分区：
文献类型：
--
作者：
Wattanapanitch, Woradorn;Fee, Michale;Sarpeshkar, Rahul
介绍了一种超低功耗神经记录放大器。该放大器似乎是迄今为止报道的最低功率和最节能的神经记录放大器。我们描述了低噪声设计技术，帮助神经放大器实现输入参考噪声，接近任何使用差分对作为输入级的放大器的理论极限。由于神经放大器在实践中必须包括差分输入对，以允许对共模和电源噪声进行鲁棒抑制，因此我们的设计似乎接近理论允许的最佳值。放大器的带宽可以调节，以记录神经尖峰或局部场电位（LFPs）。当配置用于记录神经尖峰时，放大器产生40.8 dB的中频增益和从45 Hz到5.32 kHz的3 dB带宽；放大器的输入参考噪声测量值为3.06 μ V-rms，而2.8 v电源的功耗为7.56 μ W，噪声效率因子（NEF）为2.67，理论极限为2.02。当配置为记录lfp时，放大器实现了40.9 dB的中频增益和392 mHz至295 Hz的3 dB带宽；输入参考噪声为1.66 μ V-rms，而2.8 v电源消耗2.08 μ W，对应的NEF为3.21。该放大器采用AMI的0.5 μ m CMOS工艺制造，芯片面积为0.16 mm(2)。我们用这种放大器成功地记录了麻醉的斑胸草雀大脑桡足核（RA）的动作电位。我们对放大器的性能和噪声的实验测量与理论和电路仿真相吻合。
This paper describes an ultralow-power neural recording amplifier. The amplifier appears to be the lowest power and most energy-efficient neural recording amplifier reported to date. We describe low-noise design techniques that help the neural amplifier achieve input-referred noise that is near the theoretical limit of any amplifier using a differential pair as an input stage. Since neural amplifiers must include differential input pairs in practice to allow robust rejection of common-mode and power supply noise, our design appears to be near the optimum allowed by theory. The bandwidth of the amplifier can be adjusted for recording either neural spikes or local field potentials (LFPs). When configured for recording neural spikes, the amplifier yielded a midband gain of 40.8 dB and a 3-dB bandwidth from 45 Hz to 5.32 kHz; the amplifier's input-referred noise was measured to be 3.06 mu V-rms while consuming 7.56 mu W of power from a 2.8-V supply corresponding to a noise efficiency factor (NEF) of 2.67 with the theoretical limit being 2.02. When configured for recording LFPs, the amplifier achieved a midband gain of 40.9 dB and a 3-dB bandwidth from 392 mHz to 295 Hz; the input-referred noise was 1.66 mu V-rms while consuming 2.08 mu W from a 2.8-V supply corresponding to an NEF of 3.21. The amplifier was fabricated in AMI's 0.5-mu m CMOS process and occupies 0.16 mm(2) of chip area. We obtained successful recordings of action potentials from the robust nucleus of the arcopallium (RA) of an anesthesized zebra finch brain with the amplifier. Our experimental measurements of the amplifier's performance including its noise were in good accord with theory and circuit simulations.